Didn't you have watercooled 68xx series cards? Is your 2600k under water at that high of volts? What voltage is your 7970 at? I think I got a dud 7970 for OC'ing
I did have watercooled 6950s in crossfire. I got sick of games not being optimized for crossfire, in that they either don't utilize the second card, or they do but it's glitched in some way (stutter, flickering, physics issues, etc.). So I sold them off and got a 7970 with a full cover water block. I originally planned to get a GTX 680, but the price was right on the card I got, and I may decide to do mining again later.
CPU is definitely under water. Never goes above 60-65C at those volts, and I have to really be pushing it in Prime95. It's not a 24/7 voltage since I OCed with turbo boost enabled. CPU degradation is a possibility in the long run, but that will give me an excuse to upgrade.
My 7970 is at 1.3v. It's about as high as I want to go until others can confirm the card has a safe higher voltage. RAM voltage is stock.
This overclock is slightly unstable, but only in furmark. Furmark is unrealistic GPU stressing, though (of course, I probably can't mine at these clocks either). I can game and bench all day with these clocks. Furmark crashes it within about 10 minutes. Not even a heat issue either. The card never goes above 48C in furmark, and 40-43C in games.
This post was edited on 12/21 at 2:32 pm